Numerical simulation of electromagnetic field impact on turbulent flow in the mold region of a slab caster with three different casting speeds
Sprache des Titels:
Proceedings of 5th ESTAD 2021
Continuous casting has evolved to the most important manufacturing process in the steel industry. The flow pattern in the mold of the continuous casting process is a crucial factor in determining the quality of the final product of steel slabs and can heavily influence the manufacturing costs. The casting speed is one of the major parameters which has a great influence on the mold flow pattern, and consequently on surface defects. Slow casting speed can lead to meniscus freezing and hook formation. On the other hand, high casting speed can contribute to slag entrainment and level fluctuation, which are detrimental for steel quality. Thus, a too low surface velocity and an excessive surface velocity should be avoided to prevent inclusions entrapment into the solidification shell and slag entrainment into the molten steel flow, respectively. Transient turbulence-induced flow phenomena are becoming more important in the continuous casting of steel since they can cause quality problems. In this study, three different casting speeds are investigated through fluid flow simulations in the mold region of a slab caster. The scale adaptive simulation (SAS) turbulence model is employed due to its large eddy simulation (LES)-like capability to resolve the above-mentioned transient phenomena. The comparison reveals different flow behaviors and increased level fluctuations with increasing casting speed. In the next step, local electromagnetic braking (EMBr) is applied, and the steel flow is decelerated proportional to the magnetic field to be controlled and stabilized. The results provide first guidelines for creating and maintaining a stable double roll flow and optimal meniscus velocity for high casting speed by using electromagnetic braking.